Approximate match between two matrices

i have two vectors C1 is calculated using code and A1 is input vector. C1(1x4) = [0.4311 0.123 0.011 0.441] , A1(5x4)=

X A B C

0.11 0.13 13.46 0.87

0.01 0.10 10.47 0.90

0.44 0.12 12.19 0.88

0.43 0.09 9.24 0.91

0.06 0.07 7.15 0.93

Need to find approximate match between individual C1 value with A1(:,1) and should give the coresponding output of A(:,2),A(:,3) & A(:,4).

Answer 1

[Arif Hoq]

if there is no approximate value then it will return the minimum value of that column.

C1= [0.4311 0.123 0.011 0.441];
A1=[0.11,0.13,13.46,0.87;0.01,0.10,10.47,0.90;0.44,0.12,12.19,0.88;...
    0.43,0.09,9.24,0.91;0.06,0.07,7.15,0.93 ];
A2=A1(:,1);
A3=A1(:,2);
A4=A1(:,3);
A5=A1(:,4);
[minValue1,nearestIndex] = min(abs(A2-C1(1,1)));
C1_first = A2(nearestIndex) % for the value C1=0.4311

C1_first = 0.4300

[minValue2,nearestIndex] = min(abs(A3-C1(1,2)));
C1_second = A3(nearestIndex) % for the value C1=0.123

C1_second = 0.1200

[minValue3,nearestIndex] = min(abs(A4-C1(1,3)));
C1_third = A4(nearestIndex) % for the value C1=0.011

C1_third = 7.1500

[minValue4,nearestIndex] = min(abs(A5-C1(1,4)));
C1_fourth = A5(nearestIndex) % for the value C1=0.441

C1_fourth = 0.8700

[Arif Hoq]

Or

idx = interp1(A2,1:length(A2),C1(1,1),'nearest');
C1_first = A2(nearestIndex) % for the value C1=0.4311

[Mohammed Rasul Iqbal]

Thank You Arif

[Voss]

As an alternative to the first method:

C1 = [0.4311 0.123 0.011 0.441];
A1 = [0.11,0.13,13.46,0.87; ...
    0.01,0.10,10.47,0.90; ...
    0.44,0.12,12.19,0.88;...
    0.43,0.09,9.24,0.91; ...
    0.06,0.07,7.15,0.93];

[min_diff,idx] = min(abs(A1-C1),[],1)

min_diff = 1×4

0.0011 0.0030 7.1390 0.4290

idx = 1×4

4 3 5 1

nearest_A1 = A1(sub2ind(size(A1),idx,1:size(A1,2)))

nearest_A1 = 1×4

0.4300 0.1200 7.1500 0.8700